Printer head release mechanism

ABSTRACT

On printer (20), tape cartridge (4) is detachable relative to mounting unit (5). Mounting unit (5) is covered by cover (22). When cover (22) is closed, its protrusion (51) rotates rotary component (54), and its operating edge (54b) moves moving component (55). When operating edge (54b) moves over the top edge of surface A of guiding surface (55a) of the moving component, the cover is completely closed. Subsequently, rotary component (54) is guided to surface B, where it is held in a coupled state. In conjunction with moving component (55), head carrier component (59) rotates, and head (6) located at the tip of the head carrier component becomes fixed at the print position. In the condition in which a print position is formed, rotary component (54) is off from protrusion (51) of the cover. Therefore, no load acts from the side of head (6) onto the side of cover (22). When cover-opening button (24) is pushed down, rotary component (54) disengages from surface B of the moving component, thus creating a condition in which the head has been released.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to a printer that is provided with amounting unit for mounting a cartridge containing a recording medium.More specifically, it relates to a head release mechanism for printersof this form, capable of moving the print head, relative to therecording medium supplied from a mounted cartridge, to the printposition and to a release position that is away from the print position.

2. Description of the Related Art

Printers referred to as tape printers and label printers have come intouse in recent years. In general, the recording media used on this typeof printer are tape-shaped media. The backside of such a recordingmedium is an adhesive surface covered by a piece of peel-off paper. Therecording medium is stored in a cartridge in a spooled form. Acartridge-mounting unit for mounting the cartridge on a detachable basisis formed on the printer side. The cartridge-mounting unit is covered bya cover and is configured in such a way that one opens the cover tomount a cartridge, closes the cover, and then performs printing.

A head release mechanism is incorporated into the printer so that theprint head that prints on the recording medium supplied from the mountedcartridge is not damaged when the cartridge is attached or detached andso that the print head does not hinder the cartridge attaching ordetaching operation. The head release mechanism moves the print headfrom the print position, protruding to the recording medium side, to therelease position, which is away from the print position.

FIG. 11A shows a conventional printer called a tape printer. Asindicated in the figure, the first half of the top portion of printer 1is keyboard 2. The second half is opening/closing cover 3. When cover 3is opened, as illustrated in the figure, mounting unit 4 for tapecartridge 4 (see FIG. 11B) formed inside the cover comes into view. Headunit 7, with a built-in thermal head 6 as a print head, is provided onmounting unit 5. As shown in FIG. 12, tape cartridge 4 holds, in itscase 41, roll 8 for tape-form recording medium T and roll 9 for inkribbon R. A transport path is formed so that these items become stackedat the position in which they pass through platen roll 42.

Formed adjacent to platen roll 42 is a head unit insertion hole 43through which head unit 7 is inserted when a tape cartridge is mounted.Thermal head 6, which is incorporated in head unit 7 that is insertedinto hole 43, can be moved by the head release mechanism built into theprinter, from the print position (indicated by the solid line in thefigure) protruding to the side of platen roll 42 to the release position(indicated by dashed lines in the figure) that is located in the back.

The conventional head release mechanism basically comprises a headcarrier component that supports thermal head 6 to allow the thermal headto move from the print position to the release position, a springcomponent that always holds the component onto the side of the headrelease position, a moving component that moves the head carriercomponent to the print position against the spring force of the springcomponent, and a locking component that locks the head carriercomponent, that has moved to the print position, in the new position.The head release mechanism of this composition is incorporated into thebackside of the cartridge-mounting unit.

In printer 1 shown in FIG. 11A, the moving component that moves thermalhead 6 to the print position is protrusion 31 that is formed on thebackside of cover 3. When cover 3 is closed, protrusion 31 intrudes intohole 11, formed on the case side, and moves the internally provided headcarrier component toward the print position against the spring force.Therefore, when cover 3 is closed, against the spring force, the headcarrier component is moved by protrusion 31 in conjunction with theclosing operation. This causes head 6, held at that location, toprotrude into the print position. When cover 3 is completely closed,hook 32, formed on the front edge of cover 3, is inserted into hole 12,that is formed on the case side. The hook couples with the hookengagement unit formed in the interior of the hole. This causes thecover to be locked in the closed condition. Thus, the head carriercomponent is locked into the print position.

To open cover 3, one operates cover-opening button 13. Operating button13 releases the lock and opens cover 3. As a result, the head carriercomponent released from protrusion 31 of cover 3 is returned to therelease position by the spring force. Therefore, thermal head 6 isretracted to the release position inside head unit 7. In this manner,opening cover 3 automatically creates a condition in which the head isreleased, thus permitting tape cartridge replacement and similaroperations.

In the head release mechanism of this form, protrusion 31 formedintegrally on cover 3, presses head 6 onto the print position, and hook32, formed integrally on cover 3 maintains the print state. Therefore,the pressing force that presses the head onto the print position alwaysacts on cover 3. Further, since the head load acts directly on cover 3,the head load is controlled by cover 3.

On the other hand, head release mechanisms that are not tied to theopening and closing actions of cover 3 are in the public domain. Forexample, as shown in FIG. 13, a release lever 14 is placed at a positionthat becomes exposed when cover 3 is opened. This release lever 14 ismovable from a position over tape cartridge 4, that is mounted andcentered at one end of the release lever, to a position away from thatposition. By moving lever 14 to a position above tape cartridge 4, onecan move head 6 to the print position. By moving the head from thatposition to the position indicated by the solid line in the figure, onecan retract head 6 to the release position.

In a head release mechanism in which the opening and closing actions ofcover 3 are separate from the head release operation, the tape cartridgecould be replaced inadvertently even when the head is not released(i.e., when the head is still at the print position). However, if thehead is at the print position, lever 14 is at a position that hindersthe tape cartridge replacement operation. This prevents the occurrenceof the problem mentioned above. The use of this mechanism, however,always requires a lever operation for releasing the head or for settingthe head in the print position, in addition to the operation of openingand closing cover 3.

The conventional head release mechanism described above contains thefollowing problems that must be addressed:

First, in a form in which a head release mechanism is constructed usinga cover, a protrusion formed on the cover itself presses the head ontothe print position. Therefore, the pressing force directly acts on thecover. Since load is always acting on the cover, the cover itself isliable to deform. When a deformation occurs, the head load changes withthe result that the head release mechanism can potentially lose itsability to correctly position the head in the print position.

On the other hand, in the form in which the cover and the head releasemechanism are completely separate, the release lever must be operated inorder to release the head and press it onto the print position asseparate from the operation of opening and closing the cover. While itfacilitates controlling the head load or the head position, thisrequires a lever operation each time the tape cartridge is attached ordetached, thus adding to operational complexity.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a head releasemechanism for a printer in which load does not act on the cover from theprint head.

Also, the present invention aims to provide a head release mechanism fora printer capable of moving a print head to a release position inconjunction with the operation of opening the cover.

Further, the present invention aims to provide a head release mechanismfor a printer in which load does not act on the cover from the printhead and also the printer head can be moved to release and printpositions in conjunction with the operation of opening and closing thecover.

In order to solve the above problems, the printer head release mechanismof the present invention releases the head and moves it to the printposition, in conjunction with the operation of opening and closing thecover, and adopts a constitution in which, after the head has been movedto the print position, the head load does not directly act on the cover.

That is, in a printer comprising a cartridge-mounting unit thatdetachably mounts a cartridge containing a recording medium, a coverthat covers the cartridge-mounting unit, a cover-opening button foropening the cover, a print head that prints on the recording mediumsupplied from the cartridge attached to said cartridge-mounting unit,and a head release mechanism that moves the print head to the printposition at which printing is performed on the recording medium and to arelease position that is removed from the print position, this headrelease mechanism according the present invention includes a movingmechanism that operates in conjunction with the operation for closingsaid cover and that moves said print head from said release positiontoward said print position; a locking mechanism that, when said printhead has reached said print position, releases the coupling between saidmoving mechanism and said cover and that locks said print head in saidprint position; and an unlocking mechanism that operates in conjunctionwith the operation of said cover-opening button, that releases thelocking by said locking mechanism, and that forms a coupled statebetween said moving component and said cover.

When the cover is closed and in conjunction with the closing operation,the print head in the head release mechanism of the present inventionmoves from the release position toward the print position. When theprint head has reached the print position, the moving that moves theprint head is detached from the cover and the print head is locked inthe print position by the locking mechanism. Therefore, the operation ofmoving the print head to the print position can be performed inconjunction with the operation of closing the cover. Further, in acondition in which the print head is locked in the print position, themechanical link between the cover and the print head is released. Inthis state, therefore, load does not act on the cover side, thuspreventing any deformation of the cover itself or any change in the headload. This ensures accurate locking, by the locking mechanism, of theprint head in the print position.

In a preferred embodiment of the present invention, the mechanismdescribed above are constituted as follows: first, said moving mechanismcan comprise a protrusion that is formed on said cover; a rotarycomponent that operates in conjunction with said cover-closing operationand in which the protrusion coupling end formed by said protrusion onone edge is pushed and in which the operating edge on the other end canrotate from the first position to the location immediately before thesecond position; a head carrier component that moves said thermal headfrom said release position to said print position when the head carriercomponent is pressed upon by the operating edge of the rotary componentand when said operating edge moves from said first position to thesecond position; and a head release spring component that energizes thehead carrier component in a direction so that said thermal head isalways at said release position.

The locking means described above can be provided with a guide-holdingsurface formed on the coupling surface on which the operating edge ofsaid rotary component in said head carrier component is coupled. Theoperating edge of said rotary component rotates to a locationimmediately preceding said second position, said guide-holding surfaceuses the spring force of said head release spring component to guide theoperating edge so that it rotates to the second position and disengagessaid rotary component and said protrusion. The guide-holding surface isset in a shape that enables it to maintain the operating edge of saidrotary component that has reached said second position at the secondposition through the use of the spring force of said head release springcomponent.

Further, the unlocking mechanism described above can be provided with anunlocking surface formed on said cover-opening button. When saidcover-opening button is operated, the unlocking surface forcibly movesthe operating edge of said rotary component over said guide-holdingsurface from said second position toward said first position against thespring force of said head release spring component.

In the preferred embodiment of the present invention thus constituted,the cover remains open when the print head is at the release position,and the operating edge of the rotary component is at the first position.Further, the head carrier component that carries the head is energizedby the head release spring component and is positioned in such a waythat the head is in the release position. When the cover is closed, theprotrusion that is formed there pushes and rotates the rotary componentand moves its operating edge from the first position to a locationimmediately preceding the second position. The head carrier componentmoves in conjunction with this rotation and moves the head toward theprint position. When the operating edge has rotated to a locationimmediately preceding the second position, the operating edge, guided bythe guide-holding surface formed on the head carrier component, moves tothe second position and is locked there. As a result, the protrudingengagement edge on the rotary component separates from the protrusion onthe cover, and the side of the head carrier component is locked into theprint position. Consequently, the print head is held at the printposition by the coupling between the operating edge of the rotarycomponent and the guide-holding surface of the head carrier component.Therefore, the load from the print head never directly acts on theprotrusion that is formed on the side of the cover.

On the other hand, when the cover-opening button is operated, theunlocking surface formed on the button causes the operating edge of therotary component to disengage from the print head of the head carriercomponent, thus making the rotary component rotatable toward the firstdirection. As a result, the print head moves to the release position dueto the spring force of the rotary spring component, and the cover opens.

In this manner, the head moves to the print position and the releaseoperation is performed in conjunction with the operation of opening andclosing the cover. Further, when the head is fixed in the printposition, the protrusion on the cover is removed from the rotarycomponent side, and is set in a condition wherein the head load does notact.

The present invention employs the following structure such that loaddoes not act on the cover from the printer head and the printer head canbe moved to the release position in conjunction with the operation ofopening the cover.

In a printer comprising a cartridge-mounting unit that detachably mountsa cartridge containing a recording medium, a cover that covers thecartridge-mounting unit, a cover-opening button for opening the cover, aprint head that prints on the recording medium supplied from thecartridge attached to said cartridge-mounting unit, and a head releasemechanism that moves the print head to the print position at whichprinting is performed on the recording medium and to a release positionthat is removed from the print position, said head release mechanismincludes said cover-opening button capable of moving between a coverlocked position at which said cover is kept locked and a cover openposition at which the cover separated apart from the cover lockedposition by a certain distance is unlocked, a holder mechanism forholding the cover-opening button at each of said cover locked positionand cover open positions, a print head support mechanism for movablysupporting said print head at said print position and said releaseposition, and a moving mechanism for moving said print head supportmechanism to a position at which said print head is set in said releaseposition in conjunction with the movement of said cover-opening buttonfrom said cover locked position to said cover open position.

In a head release mechanism in this structure, the cover-opening buttonworks as a head release button. That is, when the cover opening buttonis moved to the cover open position, the moving means moves the printhead support means in conjunction with the movement such that the printhead is set to the release position. The holder means allows thecover-opening button to be held at the cover locked position and thecover open position. Accordingly, the holder means receives load fromthe print head, and thus load does not act on the cover.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 shows an external view of the printer to which the presentinvention is applied;

FIG. 2 is an enlarged perspective view of the printer of FIG. 1 with itscover ajar;

FIG. 3 is a schematic diagram of the head release mechanism that isincorporated into the printer of FIG. 1;

FIG. 4A is a schematic lateral-view diagram of the head releasemechanism of FIG. 3. FIG. 4B shows a schematic planar diagram of thesame.

FIG. 5 is an explanatory diagram that shows the coupling relationshipbetween the operating edge of the rotary component that composes thehead release mechanism of FIG. 3 and the moving component;

FIG. 6 is a schematic diagram showing the geometric relationship betweenthe components in which the head in the head release mechanism of FIG. 3is set at the print position;

FIG. 7(a) is a schematic lateral-view diagram of the head releasemechanism in the condition described in FIG. 5. FIG. 7B is a schematicplanar diagram of the same;

FIGS. 8A and 8B shows the cover-locking mechanism that is incorporatedin to the printer of FIG. 1 where, FIG. 8A is a schematic diagramshowing a locked state and FIG. 8B is a schematic diagram showing anunlocked state;

FIG. 9 illustrates another example of a head release mechanism accordingto the present invention in which (A) shows a schematic diagram of themechanism and (B) illustrates the shape of a groove for sliding thecover-opening button;

FIG. 10 illustrates the head release mechanism shown in FIG. 9 in astate where the cover-opening button is slid into the cover openposition in which (A) refers to a schematic diagram for showing themovement of each component in that state and (B) shows the position ofthe cover-opening button in the sliding groove;

FIGS. 11A and 11B illustrate a conventional printer head releasemechanism in which specifically, FIG. 11A shows an external view of theprinter and FIG. 11B shows an external view of a tape cartridge mountedonto the printer;

FIG. 12 is a schematic diagram showing an internal structure of a tapecartridge;

FIG. 13 is an external view of a printer for illustrating anotherexample of a conventional head release mechanism for printer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following is an explanation of preferred embodiments of the presentinvention with reference to drawings.

Preferred Embodiment 1

FIG. 1 shows a printer to which the head release mechanism of thepresent invention is applied. The printer in this example is a tapeprinter as described in the section on prior art, wherein printing isperformed on a tape-form recording medium, on the underside of which anadhesive surface is formed. After the printing is completed, the printedrecording medium can be cut to a specified length. The recording medium,which has been cut to a prescribed length, can be affixed to a desiredlocation by peeling off the peel-off paper on the bottom so as to exposethe adhesive surface.

As shown in FIG. 1, the overall configuration of printer 20 of thisexample is the same as that of a conventional printer. The first half ofthe top portion of the printer is keyboard component 21. Cover 22 isattached to the second half. A U-shaped cut-out 22a is made at thecenter of the front edge of cover 22, at which cover-opening button 24,placed on the side of printer system unit 23, is positioned.

FIG. 2 shows the condition in which cover 22 is opened. On one side ofthe part of system unit 23 that is exposed when cover 22 is opened,cartridge-mounting unit 25 is formed to mount tape cartridge on adetachable basis. Placed on the other side is display surface 26 thatdisplays input characters. Tape cartridge 4 is identical to what isshown in FIGS. 11B and 12.

The following items protrude vertically from the bottom ofcartridge-mounting unit 25: a head unit 7, into which thermal head 6 isbuilt in; a platen roll axis 27; a ribbon take-up axis 28, a tape rollaxis 29, and so forth. A unit that accommodates these items is formed onthe side of tape cartridge 4. In a condition in which tape cartridge 4is mounted on mounting unit 24, these units 7 and axes 26 through 28 areinserted into the corresponding units that are formed on the side oftape cartridge 4, thus making possible printing operations on tape-formrecording medium T that is built into tape cartridge 4. Because thesemechanisms are identical to conventional mechanisms (see FIGS. 11B and12), a further description of the mechanisms is omitted.

In this example, hook 31, for locking the cover, is formed at a positionadjacent to cut-out 22a on the front edge of cover 22. Insertion hole 32of hook 31 is formed on the side of system unit 23. Further, lip 22b,extending from cut-out 22a to the rear edge, is formed at the center ofthe backside of cover 22. Protrusion 51, extending more or lessvertically from the backside of the cover, is formed at the center ofthat side. Insertion hole 52 of protrusion 51 is formed on the side ofsystem unit 23. Protrusion 51 is a constituent element of the headrelease mechanism of the present example.

The following is an explanation of the head release mechanismincorporated into printer 20 of the present example. As shown in FIGS.3, 4A and 4B, in the interior of printer system unit 23, a rotarycomponent 54 is provided on the backside of insertion hole 52 ofprotrusion 51 on cover 22, such that the rotary component is held in arotatable condition around axial line 53. In rotary component 54, thearm that extends from axial line 53 to the side of insertion hole 52 isapproximately L-shaped. Tip 54a of the arm is set at the coupling edgeof protrusion 51. When protrusion 51 pushes in interlocking edge 54a,rotary component 54 rotates around axial line 53, and operating edge 54bat the other end rotates upward from the first position shown in thefigure.

The operating edge 54b of rotary component 54 is always pressed againstthe coupling surface 55a of moving component 55. Moving component 55 issupported in such a way that it can move back and forth on the placeorthogonal to axial line 53 of rotary component 54. Specifically, themoving component is composed of a seating unit 55b, capable of movingback and forth along guide rail 56, and a coupling unit 55c thatprotrudes from the top surface of seating unit 55b. The front face ofcoupling unit 55c is aforementioned coupling surface 55a. On the lateralside of coupling unit 55c, a spring coupling protrusion 55d is formed,to which one end of head release coil spring 57 is attached. Coil spring57 is arranged parallel to guide rail 56. The other end is attached tospring receptacle 58 that is located at a fixed position. Therefore,moving component 55 is always pulled by coil spring 57 toward rotarycomponent 54.

Head carrier component 59 is provided on the backside of seating unit55b of moving component 55. This head carrier component 59 is providedin such a way that it can rotate around rotary axial line 60 located atits tip. Rotary axial line 60 is oriented in a direction orthogonal torotary axial line 53 of rotary component 54. Thermal head 6 is attachedto the tip of the top side of head carrier component 59 in such a waythat it coincides with rotary axial line 60. Head heat generators arearranged up and down along the front side of thermal head 6. When headcarrier component 59 rotates around axial line 60, thermal head 6rotates in an integral manner from the position indicated by the solidline in the figure to the position indicated by the dashed lines in thefigure. The position indicated by the solid line is the releaseposition; the position indicated by the dashed lines is the printposition.

The base tip side of head carrier component 59 extends to the backsideof seating unit 55b of moving component 55. Coil spring 61 links thebase edge of head carrier component 58 with seating unit 55b of movingcomponent 55, such that head carrier component 59 rotates around itsrotary axial line 60 in conjunction with the movement of movingcomponent 55.

In the head release mechanism of this constitution, whenever cover 22 isclosed, protrusion 51, that is formed integrally on the cover, pushesdown the coupling edge 54a of rotary component 54. When cover 22 iscompletely closed, hook 31 is locked by the locking mechanism (e.g.FIGS. 8A and 8B) formed on the side of the printer system unit. Whenrotary component 54 rotates, moving component 55 is pressed toward thefront side of the printer by operating edge 54b along guide rail 56.

This section explains the shape of the tip of operating edge 54b ofrotary component 54 and the shape of coupling surface 55a of movingcomponent 55 to which the tip of the operating edge is pressed. FIG. 5shows an enlarged view of these coupling units. As shown in the figure,coupling surface 55a of moving component 55, except for its top edge,forms inclined surface A that inclines to the side of rotary component54. The top edge, on the contrary, forms inclined surface B thatinclines in the opposite direction. Therefore, when the operating edge54b of the rotary component rotates along the lower-side inclinedsurface A, a force from moving component 55 acts on rotary component 54in the direction that will rotate the rotary component 54 to the lowerside shown in the figure. However, when the operating edge moves overthe top edge of inclined surface A and comes into contact with inclinedsurface B, the force from moving component 55 acts on rotary component54 in such a way that it rotates rotary component 54 to the top side asshown in the figure. Therefore, when the operating edge 54b of rotarycomponent 54 moves over the top edge of inclined surface A, rotarycomponent 54 rotates upward along inclined surface B even if it is notpressed by protrusion 51 of cover 22. If a limit on the upward rotationof rotary component 54 is set, rotary component 54 is fixed in thatposition.

In the present example, in a condition in which cover 22 is completelyclosed, the rotary component is set in such a way that the operatingedge 54b of rotary component 54 moves over the top edge of inclinedsurface A of moving component 55 by means of the action of protrusion51. Therefore, after cover 22 is completely closed, rotary component 54separates from protrusion 51 of the cover and rotates, due to the springforce of head release coil spring 57, from the dashed line positionshown in FIG. 5 to the second position of the rotation limit indicatedby the solid line. In this manner, inclined surface B of movingcomponent 55 functions as a guide-holding surface for rotary component54.

FIGS. 6 and 7A-7B show the geometric relationship between the componentsthat compose the head release mechanism in a condition in which cover 22is completely closed. In this state, the side of operating edge 54b ofrotary component 54 assumes an almost horizontal orientation. Movingcomponent 55, pushed by operating edge 54b, moves against the springforce of coil spring 57, and is in a state in which it has rotated headcarrier component 59, which is attached there, to the print position.Head 6 supported by head carrier component 59 is set in the printposition. As noted above, the coupling edge 54a of rotary component 54is located away from the top of protrusion 51 of cover 22. Therefore, inthis condition of the print position, protrusion 51 of cover 22 isphysically separate from any other constituent elements of the headrelease mechanism. Consequently, no force acts on cover 22 from the sideof head 6.

To retract the head to its release position after the head is set in theprint position, one can simply push down cover-opening button 24. Thus,in this example, as shown clearly in FIGS. 6 and 7A-7B, cover-openingbutton 24 is provided so that it is positioned directly above thecoupling surface 55a for operating edge 54b and moving component 55.When cover-opening button 24 is pushed down in order to open cover 24,operating edge 54b is also forcibly pressed downward by the lower edgesurface 24b of the button. This causes operating edge 54b to move overthe lower edge of inclined surface B to move to inclined surface A.After that, the action of coil spring 57 causes rotary component 54 torotate toward the first position, as moving component 55 moves, and toreturn to the released state shown in FIGS. 3 and 4. As moving component55 moves, head carrier component 59 also rotates, and this causes head6, supported on the tip of the head carrier component, to return to thereleased state.

Thus, the lower edge surface 24a of cover-opening button 24 functions asan unlocking surface that releases the operating edge 54b of rotarycomponent 54 from the second position so that it can rotate toward thefirst position.

The following is an explanation of the cover locking mechanism of thepresent example with reference to FIGS. 8A and 8B. As shown in thefigure, hook-coupling component 71 is attached to the lower side of hole32, into which hook 31 of cover 22 is inserted. Coupling unit 71, whilebeing supported in such a way that it can move right and left, is alwayspressed toward the side of hole 32 by a U-shaped spring unit 72 that isformed on one edge. On coupling component 71, hole 73 into which hook 31can be inserted is formed at a position opposite hole 32. Hook-couplingsurface 74 is formed on one edge of hole 73. The tip of hook 73 isbutted against coupling surface 74, and is inserted into the hole insuch a way that the coupling surface is pressed in a horizontaldirection. When hook 31 is completely inserted, a condition is formed inwhich the coupling surface 31a of hook 31 is coupled to the backside ofcoupling surface 74.

Button-coupling surface 75, coupled to the lower edge surface 24b ofcover-opening button 24, is formed on coupling component 71. When button24 is pressed, coupling component 71 is forcibly pressed sideways. Whencoupling component 71 is pressed sideways, coupling surface 74, formedon the coupling component, disconnects from hook 31. This is shown inFIG. 8B. Since cover 22 is always energized in the opening direction bymethods that are the public domain, such as screw springs, the coveropens automatically when the lock is released. When the pressing downaction on button 24 ceases, coupling component 71 moves horizontally andis returned to is original position by the spring force of spring unit72 of coupling component 71. Further, coupling component 71 also pushesbutton 24. This causes the button to move upward and return to itsoriginal, protruding position.

Preferred Embodiment 2

FIGS. 9 and 10 show another example of the head release mechanismstructure according to the present invention. The head release mechanismshown in these figures is applicable to printer 20 whose entirestructure is shown in FIGS. 1 and 2. In such cases, protrusion 51 formedon the back side of cover 22 and hole 52 into which the protrusion goeswould not be necessary. Also, hook 31 formed on cover 22 and a lockmechanism with which hook 31 engages (see FIG. 8) would not benecessary. Since the structure is identical except for these components,only a structure of the head release mechanism will be discussed belowand the entire structure of a printer will not be discussed.

The head release mechanism according to this embodiment has acover-opening button 101 which can slide along the upper surface of body23. The cover-opening button 101 is equivalent to cover-opening button24 of the previous embodiment. A cover-opening button 101 of thisembodiment includes a head 102 provided for operation conducted withfingers by an operator and a laminar leg 103 extending downward from theback side of the head. The cover-opening button 101 in this structurecan slide between cover locked position 101A adjacent to the front edgeof a cover 22 (indicated by a solid line in the figure) and cover openposition 101B indicated by a solid line in FIG. 10, along slide groove104 formed in body 23. Slide groove 104 has coupling surfaces 105 and106 formed therein, which allows leg 103 of cover-opening button 101 toengage with coupling surface 105 at cover locked position 101A andcoupling surface 106 at cover open position 101B. Cover-opening button101 is energized by spring 107 in the direction such that the engagementwith each of coupling surfaces 105 and 106 can be held.

A overhanging lip 108 is formed between head 102 and leg 103 incover-opening button 101. Hooking claw 109 formed on the front edge ofcover 22 can engage with lip 108 from the lower side. FIG. 9 shows astate in which cover-opening button 101 is at cover locked position 101Aas indicated by a solid line, which presents a state in which thecover's hooking claw 109 is engaged with lip 108 of cover-opening button101. That is, cover 22 is in a locked state.

Inside of body 23 is disposed rotary cam 110 in a manner that the camcan rotate around rotary axial line 111 which extends horizontally.Upper hooking protrusion 112 of rotary cam 110 projects toward cover 22to be kept in contact with a side 103a of leg 103 of said cover-openingbutton 101 opposing to cover 22. Therefore, when cover-opening button101 is slid toward cover open position 101B, leg 103 rotates rotary cam110 counterclockwise, facing to the drawing.

Lower hooking protrusion 113 of rotary cam 110 projects in the samedirection as upper hooking protrusion 112 to be kept in contact withinterlocking member 120. Interlocking member 120 is disposed so that itcan slide between position 120A as indicated by a solid line in FIG. 9and position 120B as indicated by a solid line in FIG. 10. Therefore,when rotary cam 110 rotates anti-clockwise, interlocking member 120 ispushed by lower hooking protrusion 113 and thus slides toward position120B.

The other side of interlocking member 120 is kept in contact with thebase edge of head carrier member 130 that carries print head 6 at thetip. Head carrier member 130 performs the same function as head carriermember 59 as described with reference to Embodiment 1 (see FIG. 3). Thatis, head carrier member 130 carries the print head 6 such that it canrotate print head 6 around rotary axial line 60 to be at print position6A as indicated by a solid line in FIG. 9 and at release position 6B asindicated by a solid line in FIG. 10.

Head carrier member 130 is always pulled at the middle of it by headpressure spring 140 toward the direction of rotating print head 6 toprint position 6A. The spring force of this spring allows head carriermember 130 and interlocking member 120 to be kept in contact,interlocking member 120 and lower hook protrusion 113 of rotary cam 110to be kept in contact, and upper hook protrusion 112 of rotary cam 110and leg 103 of cover-opening button 101 to be kept in contact.

Further, cover 22 is always pressed into the direction of opening bypop-up spring 150. Therefore, hooking claw 109 of cover 22 is pressedagainst lip 108 of cover-opening button 101 from the lower side throughthe spring force.

Now, the operation of a head release mechanism constructed in thismanner will be discussed. In a state in which cover 22 is locked asshown in FIG. 9, when cover-opening button 101 moves slightly againstthe spring force of spring 107 in a direction orthogonal to the sidingdirection, leg 103 comes off coupling surface 105 of slide groove 104.Therefore, from this point on, cover-opening button 101 can be movedagainst the force of head pressure spring 140 toward cover open position101B along slide groove 104.

When cover opening button 101 is moved along slide groove 104, lip 108comes off hooking claw 109 of cover 22. Consequently, cover 22 opensautomatically through the force of pop-up spring 150.

When cover-opening button 101 is moved to the cover open position 101B,cover-opening button 101 is pushed in a direction orthogonal to thesliding direction by the spring force of spring 107 to engage leg 103with coupling surface 106. As a result, cover-opening button 101 is tobe held at cover open position 101B.

When cover-opening button 101 slides, leg 103 allows rotary cam 110 torotate anti-clockwise. As a result, rotary cam 110 allows interlockingmember 120 to move from position 120A to position 120B. This allows headcarrier member 130 to rotate around rotary axis 60, which in turn allowsprint head 6 held at the tip to rotate from print position 6A to releaseposition 6B and to be held there.

Thus, in a head release mechanism according to this embodiment, cover 22can be moved to its release position in conjunction with the operationof opening cover 22.

In order to put print head 6 back to print position 6A, the operation inreverse to the foregoing may be performed. That is, cover 22 is closed,and cover-opening button 101 is pushed slightly against the spring forceof spring 107 in a direction orthogonal to the sliding direction whilecover 22 remains closed. As a result, leg 103 of cover-opening button101 comes off coupling surface 106 of slide groove 104. Then, by theforce of head pressure string 140, head carrier member 130 rotates backto the previous position to have print head 6 returned to print position6A. The movement of head carrier member 130 is communicated tocover-opening button 101 via interlocking member 120 and rotary cam 110to push back cover-opening button 101 to cover locked position 101A.Cover-opening button 101 returned to cover locked position 101A goesinto coupling surface 105 through the spring force of spring 107, and isheld at cover locked position 101A. When reached at cover lockedposition 101A, lip 108 of cover-opening button 101 runs onto hookingclaw 109 of cover 22 which is held in a closed state. Accordingly, cover22 is now back in a locked state.

In a state in which cover 22 is locked, the spring force of headpressure spring 140 or load acting on print head 6 travels through headcarrier member 130, interlocking member 120 and rotary cam 110 to reachcover-opening button 101. However, load passed onto cover-opening button110 is supported by the inner rim of slide groove 104 formed in the body23, and thus does not reach the side of cover 22. Accordingly, unlike aconventional method, such problems can be prevented as those occur whencover 22 supports load from a print head.

Applicability in the Art

As described above, the head release mechanism of the present inventionpermits the releasing of the print head by the unlocking of the cover.Further, in a condition in which the cover is completely closed and theprint head is fixed in the print position, the side of the cover is heldin a state in which it is physically separate from the other constituentelements of the head release mechanism. This prevents any force fromacting on the cover side from the print head side.

Therefore, according to the present invention, in contrast to theconventional mechanism in which a cover is used as part of a headrelease mechanism, the cover neither becomes deformed because of theaction of head load on it nor does the head load change due to adeformation of the cover. This ensures that the head load is maintainedat an appropriate value.

Further, in contrast to conventional mechanisms in which independenthead release operating components are employed, the head can be releasedin conjunction with the operation of opening the cover. This eliminatethe need for separate head release operations and results in a simplerprinter operation.

What is claimed is:
 1. A printer head release mechanism for use in aprinter defining a recess to releasably mount a recording mediumcartridge therein and including a print head and a printer cover tocover the recording medium cartridge when the removable medium cartridgeis mounted within the printer, the printer head release mechanismcomprising:a rotary member pivotable about a transverse axis thereof andincluding an operating arm and an opposing coupling arm to releasablyengage the printer cover when the printer cover moves to cover therecording medium cartridge; a head moving member in slidable frictionalengagement with said operating arm of said rotary member and movablebetween a first position and a second position within the printer alonga guide affixed to the printer proximate the printer recess when theprinter cover moves to cover the recording medium cartridge; a springcoupling said head moving member to a fixed spring receptacle within theprinter proximate the printer guide and biasing said head moving memberagainst said operating arm of said rotary member towards the firstprinter position; and a head carrier member coupled to said head movingmember and the print head to position the print head away from therecording medium cartridge and bring the print head into contact withrecording medium contained in the recording medium cartridge as saidhead moving member moves towards the second printer position.
 2. Theprinter head release mechanism of claim 1, wherein the printer covercomprises an integral protrusion extending into frictional contact withsaid coupling arm of said rotary member when the printer cover moves tocover the recording medium cartridge which pivots said rotating memberabout said transverse axis and causes said operating arm of saidrotating member to push said head moving member from the first printerposition towards the second printer position.
 3. The printer headrelease mechanism of claim 1, wherein said head moving member engagessaid operating arm of said rotary member along a coupling surface, saidhead moving member coupling surface including a first portion inclinedtoward said operating arm of said rotary member to induce movement ofsaid head moving member toward said first position and an adjoiningsecond portion inclined away from said operating arm of said rotarymember to lockably engage said rotary member with said head movingmember independent of the printer cover when said head moving membermoves towards the second printer position.
 4. The printer head releasemechanism of claim 2, wherein said head moving member engages saidoperating arm of said rotary member along a coupling surface, said headmoving member coupling surface including a first portion inclined towardsaid operating arm of said rotary member to induce movement of said headmoving member toward said first position and an adjoining second portioninclined away from said operating arm of said rotary member to lockablyengage said rotary member with said head moving member independent ofthe printer cover protrusion when said head moving member moves towardsthe second printer position.
 5. A printer head release mechanism for usein a printer including a print head and an printer cover movable betweenopen and closed positions, the printer head release mechanismcomprising:a rotary member pivotable about a transverse axis thereof andincluding an operating arm and an opposing coupling arm to releasablyengage the printer cover when the printer cover is closed; a head movingmember in slidable frictional engagement with said operating arm of saidrotary member and movable between a first position and a second positionwithin the printer along a fixed guide when the printer cover is closed;a spring coupling said head moving member to a fixed spring receptaclewithin the printer proximate the fixed guide and biasing said headmoving member against said operating arm of said rotary member towardsthe first printer position; and a head carrier member coupled to saidhead moving member and the print head to position the print head awayfrom recording medium contained in the printer and bring the print headinto contact with the recording medium as said head moving member movestowards the second printer position.
 6. The printer head releasemechanism of claim 5, wherein the printer cover comprises an integralprotrusion extending into frictional contact with said coupling arm ofsaid rotary member when the printer cover is closed to pivot saidrotating member about said transverse axis and cause said operating armof said rotating member to push said head moving member from the firstprinter position towards the second printer position.
 7. The printerhead release mechanism of claim 5, wherein said head moving memberengages said operating arm of said rotary member along a couplingsurface, said head moving member coupling surface including a firstportion inclined toward said operating arm of said rotary member toinduce movement of said head moving member toward said first positionand an adjoining second portion inclined away from said operating arm ofsaid rotary member to lockably engage said rotary member with said headmoving member independent of the printer cover when said head movingmember moves towards the second printer position.
 8. The printer headrelease mechanism of claim 6, wherein said head moving member engagessaid operating arm of said rotary member along a coupling surface, saidhead moving member coupling surface including a first portion inclinedtoward said operating arm of said rotary member to induce movement ofsaid head moving member toward said first position and an adjoiningsecond portion inclined away from said operating arm of said rotarymember to lockably engage said rotary member with said head movingmember independent of the printer cover protrusion when said head movingmember moves towards the second printer position.
 9. A printer forprinting information on recording a medium stored therein, comprising:anexternal cover movable between open and closed positions for accessingsaid recording medium; a print head in releasable communication withsaid recording medium; and a printer head release mechanism incommunication with said print head, comprising:a rotary member pivotableabout a transverse axis thereof and including an operating arm and anopposing coupling arm to releasably engage said external cover when saidexternal cover is closed; a head moving member in slidable frictionalengagement with said operating arm of said rotary member and movablebetween a first position and a second position within the printer alonga fixed guide when said external cover is closed; a spring coupling saidhead moving member to a fixed spring receptacle within the printerproximate said fixed guide and biasing said head moving member againstsaid operating arm of said rotary member towards the first printerposition; and a head carrier member coupled to said head moving memberand said print head to position said print head away from said recordingmedium and bring said print head into contact with said recording mediumas said head moving member moves towards the second printer position.10. The printer of claim 9, wherein said external cover comprises anintegral protrusion extending into frictional contact with said couplingarm of said rotary member when said external cover is closed to pivotsaid rotating member about said transverse axis and cause said operatingarm of said rotating member to push said head moving member from thefirst printer position towards the second printer position.
 11. Theprinter of claim 9, wherein said head moving member engages saidoperating arm of said rotary member along a coupling surface, said headmoving member coupling surface including a first portion inclined towardsaid operating arm of said rotary member to induce movement of said headmoving member toward said first position and an adjoining second portioninclined away from said operating arm of said rotary member to lockablyengage said rotary member with said head moving member independent ofsaid external cover when said head moving member moves towards thesecond printer position.
 12. The printer of claim 10, wherein said headmoving member engages said operating arm of said rotary member along acoupling surface, said head moving member coupling surface including afirst portion inclined toward said operating arm of said rotary memberto induce movement of said head moving member toward said first positionand an adjoining second portion inclined away from said operating arm ofsaid rotary member to lockably engage said rotary member with said headmoving member independent of said external cover protrusion when saidhead moving member moves towards the second printer position.